Creating a heatmap

Changing the heatmap's appearance

The Radius slider sets the radius of influence in pixels. Higher values result a smoother appearance.

The Opacity slider controls how transparent the heatmap colors are.

The optional Weight column adjusts each point's importance by multiplying its intensity by the specified column value.

Limits

Heatmaps use the Maps API Heatmap layer, so they pull data into the browser before displaying it. This is unlike Fusion Tables feature maps that render map tiles on the server. Because of this, only the first 1,000 rows are mapped. You can add filters to your map to keep the row count under the limit.

Heatmaps of geocoded addresses can be viewed in Fusion Tables but cannot be published. Publishing would extract the geocodes, which is not allowed by the Google Geocoding API's usage limits.

Publishing

The HTML/JavaScript generated in the dialog shown with Tools > Publish uses the Fusion Tables API to fetch the rows, parse them for use in the heatmap, and draw the map. If you plan to have more than minimal traffic for the map, you need to get an API key and enter it into the publish dialog's API key field. That will be included in the generated code.